Continuous tunnel borer



Feb. 3, 1,970v G. SCHONFELD CONTINUOUS TUNNEL BORER Filed NOV. 20, 1967IN VEN TOR. e011 UCHOIIFELD Feb."3, 1.970 l G. scHoNFE-LD 4 33,453,155

CONTINUOUS TUNNEL BORER Filed NOV. 20, 1967 4 Sheets-Sheet 2 INVENTORQGe org scuoNFELD BY m Attorney G. SCHONFELD CONTINUOUS TUNNEL oRER Feb.3, 1970 4 Sheets-Sheet 3 Filed NOV. 20, 1967 mm W. m s m.

Feb. 3, 1970 G. scHoNFE-LD CONTINUOS TUNNEL 130mm 4 Sheets-Sheet 4 FiledNOV. 20, 1967 INVENTOR. Gear; mmv BY 125' W0 United States Patent US.Cl. 299-31 8 Claims ABSTRACT OF THE DISCLOSURE Tunnel-boring machinewith a generally frustoconical rotary head spanned by one or more ribseach carrying an array of independently rotatable chisels, the headfurther having scoops disposed adjacent the chisels and concave in thedirection of rotation for gathering muck and depositing it on arearwardly extending conveyor passing through a tubular stem of the headslidably lodged in a cylindrical housing which is immobilizable, by aset of radial jacks, with reference to the wall of a tunnel drilled bythe boring head. Axially extending thrust jacks on the housing serve forthe longitudinal propulsion of the boring head and its stem withreference to the housing whereupon, by means of another set of radialjacks on the head itself, the latter may be immobilized and the housingmay be pulled after it upon retraction of the first-mentioned radialjacks. The boring head may be provided with a separable neck which, upondetachment from the head, may be withdrawn from the tunnel together withthe housing and with a central drill bit normally projecting beyond theboring head.

My present invention relates to a continuous boring machine to be usedfor excavating underground passages, such as tunnels or adits to mines,or for removing ores, coal or other minerals from subsurface locations.

Recent developments in this field, as described in an article by ThomasE. Howard (Scientific American, November 1967), include a continuoustunnel borer with a cutting or boring head rotating about asubstantially horizontal axis, the head carrying a peripheral array ofexcavating tools working against the tunnel face under the thrust of aset of axially oriented jacks which are mounted on a twopart machinehousing. The forward part of the housing, directly behind the head, isimmobilized with reference to the tunnel wall by radially oriented jacks(i.e. telescoping legs) during the excavating operation, the rear partof the machine housing being simultaneously pulled forward; thereafter,the rear housing part is similarly immobilized and the front part isreleased in order to move up to a position just behind the headwhereupon the cycle can be repeated.

An object of my present invention is to provide an improved machine ofthis description which, by virtue of greater compactness, operates moreefficiently and is not limited to straight-line advances.

Another important object of this invention is to provide improvedcutting and muck-gathering means on the boring head of such a machine inorder to increase its operating eii'iciency, particularly when workingin relatively hard rock.

It is also an object of my invention to provide means for facilitatingthe extraction of the greater part of the machine, minus its boringhead, after the excavation of a blind underground passage.

The boring head of a tunneling machine according to the invention is ofgenerally frustoconical, forwardly diverging configuration and isprovided at its open front end with one or more radial sets ofexcavating tools ice which are preferably mounted on radial ribsspanning this front end. The boring head also carries a plurality ofangularly spaced scoops designed to gather the muck or detritus brokenloose by the excavating tools and to dump it on a transport device, suchas an endless band conveyor, for removal toward the rear through thegenerally cylindrical machine housing. This arrangement, with thelarge-diameter machines primarily contemplated herein, still leaves roomfor maintenance personnel to Walk or crawl through the housing forinspection or repair work at the boring site. Advantageously, theexcavating tools form a stepped array which slopes forwardly in aradially inward direction; thus, these tools may be rotary chiselsindependently journaled on respective axes which are parallel to thegeneratrices of a forwardly converging imaginary cone surface centeredon the boring-head axis, the scoops extending forwardly between thetool-supporting ribs so as to terminate in the immediate vicinity ofthis imaginary cone surface While having their concave sides deepened inthe vicinity of the peripheral wall of the boring head to for-mmuckreceiving pockets therewith. The tool-supporting ribs and scoops endshort of the boring-head axis to leave free a central area through whicha drill bit extends beyond the array of excavating tools; the stem ofthis drill bit may be rotated jointly with the boring head, orindependently thereof, to dig a central channel around which the soiland rock are removed by the revolving tools.

According to another feature of my invention, the cylindrical machinehousingwhose radius is smaller than that of the array of excavatingtools on the boring head-consists of a single part fitted with a firstset of radial jacks for immobilizing the housing during the forwardthrust of the head, another set of radial jacks being provided on thehead itself whereby, upon extension of the latter jacks and retractionof the former, a reversal of the thrust-exerting plungers of an axialjack assembly pulls the housing into the tunnel after the nowirnmobilized boring head. The latter can then again be iixed in positionwhereupon, after retraction of the boring-head jacks, a new forwardthrust may be exerted upon the array of excavating tools. With thisarrangement, given two axially spaced and independently operable sets ofradial jacks on the machine housing, the latter can be limitedly tiltedin any direction so that the boring head may be steered to follow thecourse of a coal vein or otherwise advance on a path deviating from astraight line.

By providing the boring head with `a separable neck, I am able toextract the machine housing, the drill bit and the conveyor from thetunnel in a rearward direction if, for any reason, the tunnel is toremain as a blind underground passage; in this case, only the boringhead with its chisels and picks is lost.

The invention will be described in greater detail with reference to theaccompanying drawing in which:

FIG. 1 is a sectional elevational view of a tunnel-boring machine-according to the invention, shown in its position of forward thrust;

FIG. 2 is partly an end view and partly a cross-sectional view taken onthe line II-II of FIG. 1;

FIG. 3 is a side-elevational view of the machine in a 'position ofdeviation from a straight line;

FIG. 4 is a cross-sectional view taken on the line IV- IV of FIG. 3;

FIG. 5 is a detail view, drawn to a larger scale, of one of theexcavating tools on the boring head of the machine; and

FIGS. 6 and 7 are enlarged side-elevational views of other forms ofexcavating tools usable with the machine of FIGS. 1-4.

The machine shown in FIGS. 1-4 comprises a boring head, generallydesignated 1, having a frustoconical peripheral wall 4 whose open frontend is spanned by a set of ribs 3 serving as carriers for an array ofcutting tools 2; in the specific embodiment illustrated, four such ribsextend in respective radial planes 90 apart (see FIG. 2). The ribs 3slope forwardly, i.e. to the left in FIG. 1, toward the axis of rotationO of head 1 and terminate short of this axis at a central tube whichgives passage to a shaft 30 of a drill bit 7 projecting forwardly beyondthe array of excavating tools 2. The latter tools are mounted in astepped formation on the ribs 3 so that their leading edges are tangentto the generatices of an imaginary conical surface substantiallycoinciding with the tunnel face T being shaped by these tools. In theembodiment of FIG. 1, and as more clearly shown in FIG. 5, the tools 2are rotary chisels provided with annular cutting ridges 31 and journaledon individual bolts 6 Iwhose axes are more or less parallel to theassociated ribs 3, on which the studs lare mounted by brackets 27, andto the generatrices of the aforementioned imaginary surface representedin FIG. 1 by the tunnel face T. Thus, rotation of head 1 about its axisO will cause the chisels 2 to roll on the tunnel face T while bitingever more deeply into the soil around the central channel C produced bythe bit 7.

The axial staggering of the leading edges of chisels 2 result in aterracing of the tunnel face, as best seen in FIG. 5; a set of scoops 8,whose forward edges 8 extend parallel to ribs 3 in the immediatevicinity of the leading edges of chisels 2, help smooth the steppedtunnel face shown in FIG. 5 and also collect the rubble or muck producedby the chisels; toward the rear, the concave sides of the scoops 8facing in the direction of rotation (counterclockwise in FIG. 2) aredeepened so as to form pockets 9 with the frustoconical wall 4 ofhead 1. These pockets discharge, as each scoop swings above the medianhorizontal plane of the boring head 1, onto a conveyor 10 shown as anendless belt led around a forward roller 11 and a rear roller not shown.Belt 10 is driven, by means not further illustrated, in the direction ofarrow A so as to transport the deposited detritus toward the rear fromthe region of head 1. The rollers are journaled between cantilevered,axially shiftable bars 32 so that the conveyor may be withdrawn from thehead for purposes `of access, inspection or repair; shaft of bit 7 maybe similarly retractable through tube 5.

A set of webs 33, respectively aligned with ribs 3, extend from tube 5rearwardly to the narrow base of the truncated cone 4 to form supportsfor respective jacks 26 passing radially outwardly through the conewall. This wall 4 is received in a frustoconical neck 34 with which itis coupled for joint rotation by a set of axial pins and which is rigidwith a horizontal tube 12 surrounding the shaft 30 and the conveyor 10.Tube 12 is rotatably journaled, with the aid of interposed bearings 36,in a machine housing comprising two nested cylinders 15, 16 which denean annular space 17 centered on axis O. This space accommodates thecylinders 38, 39 of two axially spaced radial arrays of jacks 18 and 19,two pairs of diametrically aligned jacks being provided in each array asillustrated in FIGS. 3 and 4. In addition, the cylinder 20 of an arrayof axially extending jacks 22, centered on axis O, are also mounted inthe space 17 along with conduits 37 for reversibly displacing thesejacks, the conduit system including a reversing valve which may beoscillated at a rapid rate to impart an intermittent forward thrust tothe jacks 22 and through them to a ring 23 which presses through needlebearings 25 upon an annular shoulder 24 of neck 34. A anged outer ringer41 embraces ring 23 to insure that a reverse actuation of jacks 22 willnot disengage these jacks from the neck 34 of boring head 1. The head isfurthermore shown provided with tie rods 42, eg. three of them spaced120 apart, by which it is removably fastened t() the tube 1.2 so as tomaintain the structural unity of elements 1, 34 and 12. Upondisconnection of rods 42 from tube 12, housing 15, 16 with its jacks 18,y19 and 22 as well as tube 12 and neck 34 may be withdrawn from thetunnel without any interference from the coupling pins 35, leaving thehead 1 in place as a lost implement.

Rotation is imparted to head 1 by means of one or more motors 43 mountedin the housing space 17, each of these motors driving a pinion 44 inmesh with a ring gear 21 which is rigid with tube 12. Bit 7 may berotated in step with head 1, through a suitable coupling not shown, orindependently thereof by drive means not further illustrated.

As shown in FIGS. 6 and 7, chisels 2 may be replaced by chisels 2 or 2having a single helicoidal cutting ridge 28 or a pair of such ridges 29.Moreover, as illustrated in FIG. 2, additional chisels 14 may bedisposed on the inner periphery of cone 4 between the arrays of tools 2.

In the normal operation of the system shown in FIGS. 1 4, with jacks 22and 26 initially retracted and jacks 18 and 19 extended as illustratedin FIG. 1, bit 7 and head 1 are rotated to drill the channel C and toexcavate the tunnel face T. `During this operation, hydraulic orpneumatic Huid is admitted to the cylinders 20' to drive the head 1continuously forwardly to the limit of the stroke of jacks 22. Conveyor10 removes the oncoming debris, advancing together with head 1, shaft 30and tube 12.

When the end of the stroke of the axial jacks 22 has been reached, thedrive 43, 44, 21 of head 1 is arrested, fluid is admitted to thecylinders of jacks 26 through conduits not illustrated to extend thesejacks radially outwardly against the tunnel wall whereby the head 1 isimmobilized, and jacks 18, 19 are retracted whereupon valve 40 reversesthe connections of cylinders 2G so that these cylinders are drawnforwardly with reference to the now stationary pistons 22. By thisaction, with cylinder 15 sliding on tube 12, housing 15, 16 is againbrought into close juxtaposition with head 1 whereupon theaforedescribed cycle may be repeated with extension of jacks 18, 19,retraction of jacks 26 and forward actuation of jacks 22 while rotationof head 1 is resumed. If this actuation of jacks 22 occursintermittently as set forth above, as by a rapid alternation ofrelatively long forward thrusts with relatively short reverse movements,the fragmentizing effect of the cutting tools 2 will be enhanced.

FIGS. 3 and 4 illustrate the manner in which my improved system can beused to dig tunnels departing from straight linearity. To this end it ismerely necessary that two diametrically opposite jacks of the machinehousing, e.g. jacks 18a, 18h of the forward array of jacks 18, be leftextended during continuing rotation of head 1 so as to form a pivotalaxis P for the swing of housing 15, 16 under the control of jacks 19C,19d of the rear array 19 which stand skew to the extended jacks 18a,18b. The other jacks 18C, 18d of the front array and the remaining pairof jacks of the rear array, all operable independently, are thenextended beyond the tunnel wall to lock the machine housing in itstilted position; the boring operation then resumes as previouslydescribed. Tilting angles up to 45 can be readily achieved with thistechnique, especially if the end plates 19', 19 of the jacks arepivotally mounted on their pistons through suitable universal joints;such joints have been illustrated at 45, FIG. l, for the end plates 26of jacks 26.

I claim:

1. A tunnel-boring machine comprising a generally cylindrical housing; aboring head supported on said housing for rotation about a substantiallyhorizontal axis; a set of excavating tools on said boring head, saidtools being distributed over a radius greater than that of said housing;first radial anchoring jack means on said housing for immobilizing samewith reference to the wall of a tunnel excavated by said boring head;second radial anchoring jack means rotatvely coupled with and carried onsaid boring head for immobilizing same with reterence to the tunnelwall; retractable thrust means operatively engaging said housing andsaid boring head for axially advancing said boring head with referenceto said housing in an extended position of said irst jack means and aretracted position of said second jack means and for drawing saidhousing after said boring head in a retracted position of said lrst jackmeans and an extended position of said second jack means; and drivemeans for rotating said boring head upon retraction of said second jackmeans.

2. A tunnel-boring machine as dened in claim 1 wherein said head has aneck provided with an external annular shoulder centered on said axis,said thrust means including a plurality of peripherally spaced jacks, aring engaged by said jacks confronting said shoulder, and bearing meansbetween said ring and said shoulder.

3. A tunnel-boring machine as defined in claim 1 wherein said -rst jackmeans comprises two axially spaced radial arrays of jacks, each arrayincluding a plurality of diametrically aligned pairs of jacks, the jacksof said arrays being independently operable for enabling said housing totilt around an extended pair of jacks of one array under the control ofjacks of the other array disposed skew to said extended pair.

4. A tunnel-boring machine as defined in claim 1 wherein said thrustmeans includes a set of axial jacks and fluid-control means forintermittently actuating said jacks at a rapid rate.

5. A tunnel-boring machine as dened in claim 1, further comprising ashaft axially traversing said housing and said boring head, a drill biton said shaft projecting beyond said set of excavating tools, andconveyor means extending through said housing along said shaft into thevicinity of said boring head for the removal of muck broken loose bysaid tools.

6. A tunnel-boring machine as defined in claim 5 wherein said housingcomprises a pair of nested cylinders deining between them au annularspace centered on said axis, said tirst jack means and said thrust meansincluding fluid cylinders and supply lines lodged in said annular space,said conveyor means and said shaft extending within the inner of saidnested cylinders.

7. A tunnel-boring -machine as dened in claim S wherein said boring headis provided with a detachable neck positively engaging said housing forretraction therewith from the tunnel upon separation of said neck fromsaid boring head, said shaft and said conveyor means being withdrawablefrom said boring head with said housing.

8. A tunnel-boring machine as defined in claim 7 wherein said neck isrotatable with reference to said housing, said drive means including aring gear rigid with said neck and centered on said axis.

References Cited UNITED STATES PATENTS 3,295,892 1/1967 Winberg et al.299-31 3,307,876 3/1967 Akkerman 299-33 X 3,379,264 4/1968 Cox 175-94 XERNEST R. PURSER, Primary Examiner U.S. Cl. X.R.

